package com.bjc.principle.singleton.type2;

/**
 * @program: DesignPattern
 * @description:
 * @author: bjc
 * @create: 2020-12-13 20:28
 */
public class SingletonTest02 {


    public static void main(String[] args) {
        Singleton instance1 = Singleton.getInstance();
        Singleton instance2 = Singleton.getInstance();
        System.out.println(instance1==instance2);
        System.out.println(instance1.hashCode());
        System.out.println(instance2.hashCode());
    }
}

//饿汉式（静态代码块）
class Singleton{
    //1.构造器私有化 外部不能new
    private Singleton(){}
    //2.本类内部创建对象实例
    private static Singleton instance;

    static {  //在静态代码块中创建单例对象
        instance = new Singleton();
    }
    //3.提供一个共有的静态方法，返回实例对象
    public static Singleton getInstance(){
        return instance;
    }
}
